Railway-rated contactor relay, S00 frame
The Siemens SIRIUS 3RH2122-2XF40-2LA2 is a contactor relay designated for railway applications, built on the S00 contactor size platform. It carries 2 instantaneous NO contacts and a varistor surge suppressor built into the coil circuit. The rated control voltage spans 72 to 125 VDC, with a holding current mean value of 7 mA and an inrush current peak of 1.1 A. Pick-up time at DC is 25 to 45 ms; arcing time runs 10 to 15 ms.
Mounting and clearances
Fastens with screws or snaps onto 35 mm DIN rail. Mounting position allows hanging or horizontal surface mounting. Side-by-side mounting is permitted. Clearance distances: 10 mm upward, 10 mm forward, 10 mm downward, 6 mm at the side. Overall dimensions: 73 mm deep, 45 mm wide, 70 mm high. That 45 mm width means it occupies a single 45 mm module on the DIN rail — standard for S00 contactor relays.
Switching capacity across voltage ranges
Rated operational current varies by voltage level: 10 A at 24 V, 4.7 A at 60 V, 3 A at 110 V, 1.2 A at 220 V, 10 A at 230 V, 3 A at 400 V, 0.5 A at 440 V, 2 A at 500 V, 0.26 A at 600 V, and 1 A at 690 V. The 10 A rating at both 24 V and 230 V suggests the contacts are rated for both low-voltage DC and standard AC line voltages — common in railway auxiliary circuits where both battery and mains supplies are present.
Environmental and compliance
Operating temperature range: -40 to +70 °C; storage range: -55 to +80 °C. Relative humidity minimum 10%. The substance prohibitance date of 10/01/2009 aligns with RoHS compliance deadlines. Terminal wiring accepts 2x (0.5 to 4 mm²) solid or stranded conductors. Mechanical endurance: 30,000,000 operating cycles typical for the contactor.